Merge branch 'topic-its' into leg-kernel

10 files changed, 600 insertions, 77 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index c88307a57fd0..47ef6f1a1e3c 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -57,6 +57,9 @@ config ACPI_SYSTEM_POWER_STATES_SUPPORT
 config ACPI_CCA_REQUIRED
 	bool
 
+config IORT_TABLE
+	bool
+
 config ACPI_DEBUGGER
 	bool "AML debugger interface"
 	select ACPI_DEBUG
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 84c725a09095..603563ac2eb2 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -83,6 +83,7 @@ obj-$(CONFIG_ACPI_BGRT)		+= bgrt.o
 obj-$(CONFIG_ACPI_CPPC_LIB)	+= cppc_acpi.o
 obj-$(CONFIG_ACPI_SPCR_TABLE)	+= spcr.o
 obj-$(CONFIG_ACPI_DEBUGGER_USER) += acpi_dbg.o
+obj-$(CONFIG_IORT_TABLE) 	+= iort.o
 
 # processor has its own "processor." module_param namespace
 processor-y			:= processor_driver.o
diff --git a/drivers/acpi/iort.c b/drivers/acpi/iort.c
new file mode 100644
index 000000000000..226eb6d6f92b
--- /dev/null
+++ b/drivers/acpi/iort.c
@@ -0,0 +1,344 @@
+/*
+ * Copyright (C) 2016, Semihalf
+ *	Author: Tomasz Nowicki <tn@semihalf.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * This file implements early detection/parsing of I/O mapping
+ * reported to OS through firmware via I/O Remapping Table (IORT)
+ * IORT document number: ARM DEN 0049A
+ */
+
+#define pr_fmt(fmt)	"ACPI: IORT: " fmt
+
+#include <linux/export.h>
+#include <linux/iort.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+
+struct iort_its_msi_chip {
+	struct list_head	list;
+	struct fwnode_handle	*fw_node;
+	u32			translation_id;
+};
+
+typedef acpi_status (*iort_find_node_callback)
+	(struct acpi_iort_node *node, void *context);
+
+/* Root pointer to the mapped IORT table */
+static struct acpi_table_header *iort_table;
+
+static LIST_HEAD(iort_msi_chip_list);
+
+/**
+ * iort_register_domain_token() - register domain token and related ITS ID
+ * 				  to the list from where we can get it back
+ * 				  later on.
+ * @translation_id: ITS ID
+ * @token: domain token
+ *
+ * Returns: 0 on success, -ENOMEM if not memory when allocating list element.
+ */
+int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node)
+{
+	struct iort_its_msi_chip *its_msi_chip;
+
+	its_msi_chip = kzalloc(sizeof(*its_msi_chip), GFP_KERNEL);
+	if (!its_msi_chip)
+		return -ENOMEM;
+
+	its_msi_chip->fw_node = fw_node;
+	its_msi_chip->translation_id = trans_id;
+
+	list_add(&its_msi_chip->list, &iort_msi_chip_list);
+	return 0;
+}
+
+/**
+ * iort_unregister_domain_token() - unregister domain token based on ITS ID.
+ * @translation_id: ITS ID
+ *
+ * Returns: none.
+ */
+void iort_deregister_domain_token(int trans_id)
+{
+	struct iort_its_msi_chip *its_msi_chip, *t;
+
+	list_for_each_entry_safe(its_msi_chip, t, &iort_msi_chip_list, list) {
+		if (its_msi_chip->translation_id == trans_id) {
+			list_del(&its_msi_chip->list);
+			kfree(its_msi_chip);
+			break;
+		}
+	}
+}
+
+/**
+ * iort_find_its_domain_token() - find domain token based on given ITS ID.
+ * @translation_id: ITS ID
+ *
+ * Returns: domain token when find on the list, NULL otherwise.
+ */
+struct fwnode_handle *iort_its_find_domain_token(int trans_id)
+{
+	struct iort_its_msi_chip *its_msi_chip;
+
+	list_for_each_entry(its_msi_chip, &iort_msi_chip_list, list) {
+		if (its_msi_chip->translation_id == trans_id)
+			return its_msi_chip->fw_node;
+	}
+
+	return NULL;
+}
+
+static struct acpi_iort_node *
+iort_scan_node(enum acpi_iort_node_type type,
+	       iort_find_node_callback callback, void *context)
+{
+	struct acpi_iort_node *iort_node, *iort_end;
+	struct acpi_table_iort *iort;
+	int i;
+
+	if (!iort_table)
+		return NULL;
+
+	/*
+	 * iort_table and iort both point to the start of IORT table, but
+	 * have different struct types
+	 */
+	iort = (struct acpi_table_iort *)iort_table;
+
+	/* Get the first IORT node */
+	iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort,
+				 iort->node_offset);
+	iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+				iort_table->length);
+
+	for (i = 0; i < iort->node_count; i++) {
+		if (iort_node >= iort_end) {
+			pr_err("iort node pointer overflows, bad table\n");
+			return NULL;
+		}
+
+		if (iort_node->type == type) {
+			if (ACPI_SUCCESS(callback(iort_node, context)))
+				return iort_node;
+		}
+
+		iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node,
+					 iort_node->length);
+	}
+
+	return NULL;
+}
+
+static acpi_status
+iort_find_dev_callback(struct acpi_iort_node *node, void *context)
+{
+	struct acpi_iort_root_complex *pci_rc;
+	struct device *dev = context;
+	struct pci_bus *bus;
+
+	switch (node->type) {
+	case ACPI_IORT_NODE_PCI_ROOT_COMPLEX:
+		bus = to_pci_bus(dev);
+		pci_rc = (struct acpi_iort_root_complex *)node->node_data;
+
+		/*
+		 * It is assumed that PCI segment numbers maps one-to-one
+		 * with root complexes. Each segment number can represent only
+		 * one root complex.
+		 */
+		if (pci_rc->pci_segment_number == pci_domain_nr(bus))
+			return AE_OK;
+
+		break;
+	}
+
+	return AE_NOT_FOUND;
+}
+
+static struct acpi_iort_node *
+iort_dev_map_rid(struct acpi_iort_node *node, u32 rid_in,
+			    u32 *rid_out)
+{
+
+	if (!node)
+		goto out;
+
+	/* Go upstream */
+	while (node->type != ACPI_IORT_NODE_ITS_GROUP) {
+		struct acpi_iort_id_mapping *id;
+		int i, found = 0;
+
+		/* Exit when no mapping array */
+		if (!node->mapping_offset || !node->mapping_count)
+			return NULL;
+
+		id = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
+				  node->mapping_offset);
+
+		for (i = 0, found = 0; i < node->mapping_count; i++, id++) {
+			/*
+			 * Single mapping is not translation rule,
+			 * lets move on for this case
+			 */
+			if (id->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
+				if (node->type != ACPI_IORT_NODE_SMMU) {
+					rid_in = id->output_base;
+					found = 1;
+					break;
+				}
+
+				pr_warn(FW_BUG "[node %p type %d] SINGLE MAPPING flag not allowed for SMMU node, skipping ID map\n",
+					node, node->type);
+				continue;
+			}
+
+			if (rid_in < id->input_base ||
+			    (rid_in > id->input_base + id->id_count))
+				continue;
+
+			rid_in = id->output_base + (rid_in - id->input_base);
+			found = 1;
+			break;
+		}
+
+		if (!found)
+			return NULL;
+
+		/* Firmware bug! */
+		if (!id->output_reference) {
+			pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
+			       node, node->type);
+			return NULL;
+		}
+
+		node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+				    id->output_reference);
+	}
+
+out:
+	if (rid_out)
+		*rid_out = rid_in;
+	return node;
+}
+
+static struct acpi_iort_node *
+iort_its_find_node_and_map_rid(struct pci_dev *pdev, u32 req_id, u32 *dev_id)
+{
+	struct pci_bus *pbus = pdev->bus;
+	struct acpi_iort_node *node;
+
+	/* Find a PCI root bus */
+	while (!pci_is_root_bus(pbus))
+		pbus = pbus->parent;
+
+
+	node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
+			      iort_find_dev_callback, &pbus->dev);
+	if (!node) {
+		dev_err(&pdev->dev, "can't find related IORT node\n");
+		return NULL;
+	}
+
+	return iort_dev_map_rid(node, req_id, dev_id);
+}
+
+/**
+ * iort_pci_domain_get_msi_rid() - find MSI RID based on PCI device ID
+ * @pdev: The PCI device
+ * @req_id: The PCI device requester ID
+ *
+ * Returns: MSI RID on success, input requester ID otherwise
+ */
+u32 iort_pci_get_msi_rid(struct pci_dev *pdev, u32 req_id)
+{
+	u32 dev_id;
+
+	if (!iort_its_find_node_and_map_rid(pdev, req_id, &dev_id))
+		return req_id;
+
+	return dev_id;
+}
+
+/**
+ * iort_pci_find_its_id() - find the ITS identifier based on specified device.
+ * @pdev: The PCI device
+ * @idx: Index of the ITS identifier list
+ * @its_id: ITS identifier
+ *
+ * Returns: 0 on success, appropriate error value otherwise
+ */
+static int
+iort_pci_find_its_id(struct pci_dev *pdev, u32 req_id, unsigned int idx,
+		     int *its_id)
+{
+	struct acpi_iort_its_group *its;
+	struct acpi_iort_node *node;
+
+	node = iort_its_find_node_and_map_rid(pdev, req_id, NULL);
+	if (!node)
+		return -ENXIO;
+
+	/* Move to ITS specific data */
+	its = (struct acpi_iort_its_group *)node->node_data;
+	if (idx > its->its_count) {
+		dev_err(&pdev->dev, "requested ITS ID index [%d] is greater than available[%d]\n",
+			idx, its->its_count);
+		return -ENXIO;
+	}
+
+	*its_id = its->identifiers[idx];
+	return 0;
+}
+
+/**
+ * iort_pci_get_msi_domain_handle() - find registered domain token related to
+ *                                    PCI device
+ * @pdev:    The PCI device
+ * @req_id:  The PCI device requester ID
+ *
+ * Returns: the MSI domain for this device, NULL otherwise
+ */
+struct irq_domain *
+iort_pci_get_domain(struct pci_dev *pdev, u32 req_id)
+{
+	static struct fwnode_handle *handle;
+	int its_id;
+
+	if (iort_pci_find_its_id(pdev, req_id, 0, &its_id))
+		return NULL;
+
+	handle = iort_its_find_domain_token(its_id);
+	if (!handle)
+		return NULL;
+
+	return irq_find_matching_fwnode(handle, DOMAIN_BUS_PCI_MSI);
+}
+
+static int __init iort_table_detect(void)
+{
+	acpi_status status;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
+	if (ACPI_FAILURE(status)) {
+		const char *msg = acpi_format_exception(status);
+		pr_err("Failed to get table, %s\n", msg);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+arch_initcall(iort_table_detect);
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index fa33c50b0e5a..c6e652f47078 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -32,6 +32,7 @@ config ARM_GIC_V3
 config ARM_GIC_V3_ITS
 	bool
 	select PCI_MSI_IRQ_DOMAIN
+	select IORT_TABLE if ACPI
 
 config ARM_NVIC
 	bool
diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index aee60ed025dc..985f5d9cf4bc 100644
--- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
@@ -15,6 +15,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/iort.h>
 #include <linux/msi.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
@@ -106,34 +107,87 @@ static struct of_device_id its_device_id[] = {
 	{},
 };
 
-static int __init its_pci_msi_init(void)
+static int __init its_pci_msi_init_one(struct fwnode_handle *handle,
+				       const char *name)
 {
-	struct device_node *np;
 	struct irq_domain *parent;
 
+	parent = irq_find_matching_fwnode(handle, DOMAIN_BUS_NEXUS);
+	if (!parent || !msi_get_domain_info(parent)) {
+		pr_err("%s: Unable to locate ITS domain\n", name);
+		return -ENXIO;
+	}
+
+	if (!pci_msi_create_irq_domain(handle, &its_pci_msi_domain_info,
+				       parent)) {
+		pr_err("%s: Unable to create PCI domain\n", name);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int __init its_pci_of_msi_init(void)
+{
+	struct device_node *np;
+
 	for (np = of_find_matching_node(NULL, its_device_id); np;
 	     np = of_find_matching_node(np, its_device_id)) {
 		if (!of_property_read_bool(np, "msi-controller"))
 			continue;
 
-		parent = irq_find_matching_host(np, DOMAIN_BUS_NEXUS);
-		if (!parent || !msi_get_domain_info(parent)) {
-			pr_err("%s: unable to locate ITS domain\n",
-			       np->full_name);
-			continue;
-		}
-
-		if (!pci_msi_create_irq_domain(of_node_to_fwnode(np),
-					       &its_pci_msi_domain_info,
-					       parent)) {
-			pr_err("%s: unable to create PCI domain\n",
-			       np->full_name);
+		if (its_pci_msi_init_one(of_node_to_fwnode(np), np->full_name))
 			continue;
-		}
 
 		pr_info("PCI/MSI: %s domain created\n", np->full_name);
 	}
 
 	return 0;
 }
+
+#ifdef CONFIG_ACPI
+
+static int __init
+its_pci_msi_parse_madt(struct acpi_subtable_header *header,
+		       const unsigned long end)
+{
+	struct acpi_madt_generic_translator *its_entry;
+	struct fwnode_handle *dom_handle;
+	char node_name[6 + 16 + 1]; // ITS identification name
+
+	its_entry = (struct acpi_madt_generic_translator *)header;
+	snprintf(node_name, 23, "ITS@0x%lx", (long)its_entry->base_address);
+	dom_handle = iort_its_find_domain_token(its_entry->translation_id);
+	if (!dom_handle) {
+		pr_err("%s: Unable to locate ITS domain handle\n", node_name);
+		return 0;
+	}
+
+	if (its_pci_msi_init_one(dom_handle, node_name))
+		return 0;
+
+	pr_info("PCI/MSI: %s domain created\n", node_name);
+	return 0;
+}
+
+static int __init its_pci_acpi_msi_init(void)
+{
+	acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
+			      its_pci_msi_parse_madt, 0);
+	return 0;
+}
+#else
+inline static int __init its_pci_acpi_msi_init(void)
+{
+	return 0;
+}
+#endif
+
+static int __init its_pci_msi_init(void)
+{
+	its_pci_of_msi_init();
+	its_pci_acpi_msi_init();
+
+	return 0;
+}
 early_initcall(its_pci_msi_init);
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 5eb1f9e17a98..3ab1404281e4 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -15,10 +15,13 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/acpi.h>
 #include <linux/bitmap.h>
 #include <linux/cpu.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/iort.h>
 #include <linux/log2.h>
 #include <linux/mm.h>
 #include <linux/msi.h>
@@ -74,7 +77,7 @@ struct its_node {
 	raw_spinlock_t		lock;
 	struct list_head	entry;
 	void __iomem		*base;
-	unsigned long		phys_base;
+	phys_addr_t		phys_base;
 	struct its_cmd_block	*cmd_base;
 	struct its_cmd_block	*cmd_write;
 	struct its_baser	tables[GITS_BASER_NR_REGS];
@@ -114,6 +117,7 @@ struct its_device {
 static LIST_HEAD(its_nodes);
 static DEFINE_SPINLOCK(its_lock);
 static struct rdists *gic_rdists;
+static struct irq_domain *its_parent;
 
 #define gic_data_rdist()		(raw_cpu_ptr(gic_rdists->rdist))
 #define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)
@@ -837,7 +841,7 @@ static void its_free_tables(struct its_node *its)
 	}
 }
 
-static int its_alloc_tables(const char *node_name, struct its_node *its)
+static int its_alloc_tables(struct its_node *its)
 {
 	int err;
 	int i;
@@ -893,8 +897,8 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
 				    order);
 			if (order >= MAX_ORDER) {
 				order = MAX_ORDER - 1;
-				pr_warn("%s: Device Table too large, reduce its page order to %u\n",
-					node_name, order);
+				pr_warn("ITS@%pa: Device Table too large, reduce its page order to %u\n",
+					&its->phys_base, order);
 			}
 		}
 
@@ -903,8 +907,8 @@ retry_alloc_baser:
 		if (alloc_pages > GITS_BASER_PAGES_MAX) {
 			alloc_pages = GITS_BASER_PAGES_MAX;
 			order = get_order(GITS_BASER_PAGES_MAX * psz);
-			pr_warn("%s: Device Table too large, reduce its page order to %u (%u pages)\n",
-				node_name, order, alloc_pages);
+			pr_warn("ITS@%pa: Device Table too large, reduce its page order to %u (%u pages)\n",
+				&its->phys_base, order, alloc_pages);
 		}
 
 		base = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
@@ -978,8 +982,8 @@ retry_baser:
 		}
 
 		if (val != tmp) {
-			pr_err("ITS: %s: GITS_BASER%d doesn't stick: %lx %lx\n",
-			       node_name, i,
+			pr_err("ITS@%pa: GITS_BASER%d doesn't stick: %lx %lx\n",
+			       &its->phys_base, i,
 			       (unsigned long) val, (unsigned long) tmp);
 			err = -ENXIO;
 			goto out_free;
@@ -1335,6 +1339,11 @@ static int its_irq_gic_domain_alloc(struct irq_domain *domain,
 		fwspec.param[0] = GIC_IRQ_TYPE_LPI;
 		fwspec.param[1] = hwirq;
 		fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
+	} else if (is_fwnode_irqchip(domain->parent->fwnode)) {
+		fwspec.fwnode = domain->parent->fwnode;
+		fwspec.param_count = 2;
+		fwspec.param[0] = hwirq;
+		fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
 	} else {
 		return -EINVAL;
 	}
@@ -1507,44 +1516,59 @@ static void its_enable_quirks(struct its_node *its)
 	gic_enable_quirks(iidr, its_quirks, its);
 }
 
-static int __init its_probe(struct device_node *node,
-			    struct irq_domain *parent)
+static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
+{
+	struct irq_domain *inner_domain;
+	struct msi_domain_info *info;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	inner_domain = irq_domain_create_tree(handle, &its_domain_ops, its);
+	if (!inner_domain) {
+		kfree(info);
+		return -ENOMEM;
+	}
+
+	inner_domain->parent = its_parent;
+	inner_domain->bus_token = DOMAIN_BUS_NEXUS;
+	info->ops = &its_msi_domain_ops;
+	info->data = its;
+	inner_domain->host_data = info;
+
+	return 0;
+}
+
+static int __init its_probe_one(struct resource *res,
+				struct fwnode_handle *handle)
 {
-	struct resource res;
 	struct its_node *its;
 	void __iomem *its_base;
-	struct irq_domain *inner_domain;
 	u32 val;
 	u64 baser, tmp;
 	int err;
 
-	err = of_address_to_resource(node, 0, &res);
-	if (err) {
-		pr_warn("%s: no regs?\n", node->full_name);
-		return -ENXIO;
-	}
-
-	its_base = ioremap(res.start, resource_size(&res));
+	its_base = ioremap(res->start, resource_size(res));
 	if (!its_base) {
-		pr_warn("%s: unable to map registers\n", node->full_name);
+		pr_warn("ITS@%pa: Unable to map ITS registers\n", &res->start);
 		return -ENOMEM;
 	}
 
 	val = readl_relaxed(its_base + GITS_PIDR2) & GIC_PIDR2_ARCH_MASK;
 	if (val != 0x30 && val != 0x40) {
-		pr_warn("%s: no ITS detected, giving up\n", node->full_name);
+		pr_warn("ITS@%pa: No ITS detected, giving up\n", &res->start);
 		err = -ENODEV;
 		goto out_unmap;
 	}
 
 	err = its_force_quiescent(its_base);
 	if (err) {
-		pr_warn("%s: failed to quiesce, giving up\n",
-			node->full_name);
+		pr_warn("ITS@%pa: Failed to quiesce, giving up\n", &res->start);
 		goto out_unmap;
 	}
 
-	pr_info("ITS: %s\n", node->full_name);
+	pr_info("ITS@%pa\n", &res->start);
 
 	its = kzalloc(sizeof(*its), GFP_KERNEL);
 	if (!its) {
@@ -1556,7 +1580,7 @@ static int __init its_probe(struct device_node *node,
 	INIT_LIST_HEAD(&its->entry);
 	INIT_LIST_HEAD(&its->its_device_list);
 	its->base = its_base;
-	its->phys_base = res.start;
+	its->phys_base = res->start;
 	its->ite_size = ((readl_relaxed(its_base + GITS_TYPER) >> 4) & 0xf) + 1;
 	its->numa_node = of_node_to_nid(node);
 
@@ -1569,7 +1593,7 @@ static int __init its_probe(struct device_node *node,
 
 	its_enable_quirks(its);
 
-	err = its_alloc_tables(node->full_name, its);
+	err = its_alloc_tables(its);
 	if (err)
 		goto out_free_cmd;
 
@@ -1605,28 +1629,9 @@ static int __init its_probe(struct device_node *node,
 	writeq_relaxed(0, its->base + GITS_CWRITER);
 	writel_relaxed(GITS_CTLR_ENABLE, its->base + GITS_CTLR);
 
-	if (of_property_read_bool(node, "msi-controller")) {
-		struct msi_domain_info *info;
-
-		info = kzalloc(sizeof(*info), GFP_KERNEL);
-		if (!info) {
-			err = -ENOMEM;
-			goto out_free_tables;
-		}
-
-		inner_domain = irq_domain_add_tree(node, &its_domain_ops, its);
-		if (!inner_domain) {
-			err = -ENOMEM;
-			kfree(info);
-			goto out_free_tables;
-		}
-
-		inner_domain->parent = parent;
-		inner_domain->bus_token = DOMAIN_BUS_NEXUS;
-		info->ops = &its_msi_domain_ops;
-		info->data = its;
-		inner_domain->host_data = info;
-	}
+	err = its_init_domain(handle, its);
+	if (err)
+		goto out_free_tables;
 
 	spin_lock(&its_lock);
 	list_add(&its->entry, &its_nodes);
@@ -1642,7 +1647,7 @@ out_free_its:
 	kfree(its);
 out_unmap:
 	iounmap(its_base);
-	pr_err("ITS: failed probing %s (%d)\n", node->full_name, err);
+	pr_err("ITS@%pa: failed probing (%d)\n", &res->start, err);
 	return err;
 }
 
@@ -1670,16 +1675,91 @@ static struct of_device_id its_device_id[] = {
 	{},
 };
 
-int __init its_init(struct device_node *node, struct rdists *rdists,
-	     struct irq_domain *parent_domain)
+static int __init its_of_probe(struct device_node *node)
 {
 	struct device_node *np;
+	struct resource res;
 
 	for (np = of_find_matching_node(node, its_device_id); np;
 	     np = of_find_matching_node(np, its_device_id)) {
-		its_probe(np, parent_domain);
+		if (!of_property_read_bool(np, "msi-controller")) {
+			pr_warn("%s: no msi-controller property, ITS ignored\n",
+				np->full_name);
+			continue;
+		}
+
+		if (of_address_to_resource(np, 0, &res)) {
+			pr_warn("%s: no regs?\n", np->full_name);
+			continue;
+		}
+
+		its_probe_one(&res, &np->fwnode);
+	}
+	return 0;
+}
+
+#ifdef CONFIG_ACPI
+
+#define ACPI_GICV3_ITS_MEM_SIZE (2 * SZ_64K)
+
+static int __init gic_acpi_parse_madt_its(struct acpi_subtable_header *header,
+					  const unsigned long end)
+{
+	struct acpi_madt_generic_translator *its_entry;
+	struct fwnode_handle *dom_handle;
+	struct resource res;
+	int err;
+
+	its_entry = (struct acpi_madt_generic_translator *)header;
+	res.start = its_entry->base_address;
+	res.end = its_entry->base_address + ACPI_GICV3_ITS_MEM_SIZE - 1;
+
+	dom_handle = irq_domain_alloc_fwnode((void *)its_entry->base_address);
+	if (!dom_handle) {
+		pr_err("ITS@%pa: Unable to allocate GICv3 ITS domain token\n",
+		       &res.start);
+		return -ENOMEM;
 	}
 
+	err = iort_register_domain_token(its_entry->translation_id, dom_handle);
+	if (err) {
+		pr_err("ITS@%pa: Unable to register GICv3 ITS domain token (ITS ID %d) to IORT\n",
+		       &res.start, its_entry->translation_id);
+		goto dom_err;
+	}
+
+	err = its_probe_one(&res, dom_handle);
+	if (!err)
+		return 0;
+
+	iort_deregister_domain_token(its_entry->translation_id);
+dom_err:
+	irq_domain_free_fwnode(dom_handle);
+	return err;
+}
+
+void __init its_acpi_probe(void)
+{
+	if (acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
+				  gic_acpi_parse_madt_its, 0) <= 0)
+		pr_info("No valid GIC ITS entries exist\n");
+}
+#else
+static inline void __init its_acpi_probe(struct irq_domain *parent_domain) { }
+#endif
+
+int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
+		    struct irq_domain *parent_domain)
+{
+	struct device_node *of_node;
+
+	its_parent = parent_domain;
+	of_node = to_of_node(handle);
+	if (of_node)
+		its_of_probe(of_node);
+	else
+		its_acpi_probe();
+
 	if (list_empty(&its_nodes)) {
 		pr_warn("ITS: No ITS available, not enabling LPIs\n");
 		return -ENXIO;
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 2c5ba0e704bf..2a8b2e1c3d1c 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -911,7 +911,6 @@ static int __init gic_init_bases(void __iomem *dist_base,
 				 u64 redist_stride,
 				 struct fwnode_handle *handle)
 {
-	struct device_node *node;
 	u32 typer;
 	int gic_irqs;
 	int err;
@@ -952,10 +951,8 @@ static int __init gic_init_bases(void __iomem *dist_base,
 
 	set_handle_irq(gic_handle_irq);
 
-	node = to_of_node(handle);
-	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis() &&
-	    node) /* Temp hack to prevent ITS init for ACPI */
-		its_init(node, &gic_data.rdists, gic_data.domain);
+	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis())
+		its_init(handle, &gic_data.rdists, gic_data.domain);
 
 	gic_smp_init();
 	gic_dist_init();
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index a080f4496fe2..ba49df7afd6b 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -18,6 +18,7 @@
 #include <linux/smp.h>
 #include <linux/errno.h>
 #include <linux/io.h>
+#include <linux/iort.h>
 #include <linux/slab.h>
 #include <linux/irqdomain.h>
 #include <linux/of_irq.h>
@@ -1364,8 +1365,8 @@ u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
 	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
 
 	of_node = irq_domain_get_of_node(domain);
-	if (of_node)
-		rid = of_msi_map_rid(&pdev->dev, of_node, rid);
+	rid = of_node ? of_msi_map_rid(&pdev->dev, of_node, rid) :
+			iort_pci_get_msi_rid(pdev, rid);
 
 	return rid;
 }
@@ -1381,9 +1382,13 @@ u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
  */
 struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
 {
+	struct irq_domain *dom;
 	u32 rid = 0;
 
 	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
-	return of_msi_map_get_device_domain(&pdev->dev, rid);
+	dom = of_msi_map_get_device_domain(&pdev->dev, rid);
+	if (!dom)
+		dom = iort_pci_get_domain(pdev, rid);
+	return dom;
 }
 #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
diff --git a/include/linux/iort.h b/include/linux/iort.h
new file mode 100644
index 000000000000..490ff4de2eec
--- /dev/null
+++ b/include/linux/iort.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2016, Semihalf
+ *	Author: Tomasz Nowicki <tn@semihalf.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef __IORT_H__
+#define __IORT_H__
+
+#include <linux/acpi.h>
+
+struct fwnode_handle;
+int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node);
+void iort_deregister_domain_token(int trans_id);
+struct fwnode_handle *iort_its_find_domain_token(int trans_id);
+#ifdef CONFIG_IORT_TABLE
+u32 iort_pci_get_msi_rid(struct pci_dev *pdev, u32 req_id);
+struct irq_domain *iort_pci_get_domain(struct pci_dev *pdev, u32 req_id);
+#else
+static inline u32 iort_pci_get_msi_rid(struct pci_dev *pdev, u32 req_id)
+{ return req_id; }
+static inline struct irq_domain *
+iort_pci_get_domain(struct pci_dev *pdev, u32 req_id) { return NULL; }
+#endif
+
+#endif /* __IORT_H__ */
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index dc493e0f0ff7..21366395dcfc 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -334,9 +334,9 @@ struct rdists {
 };
 
 struct irq_domain;
-struct device_node;
+struct fwnode_handle;
 int its_cpu_init(void);
-int its_init(struct device_node *node, struct rdists *rdists,
+int its_init(struct fwnode_handle *handle, struct rdists *rdists,
 	     struct irq_domain *domain);
 
 static inline bool gic_enable_sre(void)